The present invention relates to a such lens having high resolving power as reading out the information from an object in which information is recorded with high degree of density.
A lens having high resolving power is required in a device to optically read out information using laser beam, etc. out of an information carrier in which a large volume of information is housed as in a video-disk which is becoming very popular. If a conventional miroscopic objective lens is used as a lens having high resolving power, its heavy weight presents a problem and its practical use is difficult. That is this type of lens is required to have small size, light weight and comparatively long working distance beside high resolving power. Therefore, aberration must be so corrected as exhibiting high resolving power with as simple set up as possible.